CampaignOperation

A single operation (create, update, remove) on a campaign.

Fields
update_mask	FieldMask FieldMask that determines which resource fields are modified in an update.
Union field operation operation. The mutate operation. operation can be only one of the following:
create	Campaign Create operation: No resource name is expected for the new campaign.
update	Campaign Update operation: The campaign is expected to have a valid resource name.
remove	string Remove operation: A resource name for the removed campaign is expected, in this format: customers/{customer_id}/campaigns/{campaign_id}